UK inflation has accelerated more than expected to 3.5%, driven by the fastest rise in motor fuel costs in four years, according to the Office for National Statistics (ONS). The consumer prices index (CPI) rose from 3.1% in August, surpassing economists' forecasts of 3.4%. The surge underscores growing pressure on household budgets and raises the stakes for the Bank of England's next interest rate decision.
The ONS identified transport, particularly motor fuels, as the biggest factor pushing inflation higher. Restaurant and hotel prices provided the largest partially offsetting downward contribution. Motor fuel inflation reached its highest rate since August 2022, with diesel topping £2 a litre this month and petrol climbing above £1.70.
Why Motor Fuel Costs Are Soaring
Oil and gas prices have soared since the end of February, when the US and Israel launched a war on Iran. The practical closure of the Strait of Hormuz to most fossil fuel traffic has sent Brent crude well north of $100 a barrel. This geopolitical shock has cascaded into higher pump prices, with diesel hitting a record high.
Core CPI, which excludes volatile energy, food, alcohol, and tobacco costs, rose by 2.8% in the 12 months to September, up from 2.6% in August. This suggests underlying inflationary pressures are broadening beyond just fuel.
What This Means for Interest Rates
Bank of England officials are widely forecast to raise interest rates when they meet next month, as concerns mount that inflation will remain stubbornly high. Higher fuel costs risk feeding into wider price pressures, complicating the central bank's balancing act between curbing inflation and supporting growth.
The decision will be closely watched by businesses and consumers alike. A rate hike would increase borrowing costs, potentially cooling demand but also adding to financial strain for households already grappling with elevated energy bills.
Jackdaw Gasfield Approval: A Timely Boost?
In a separate development, the UK government has approved the Jackdaw gasfield in the North Sea. The decision comes as energy security moves to the top of the political agenda, with soaring oil and gas prices highlighting the risks of reliance on imported fossil fuels.
The Jackdaw field, operated by Shell, is expected to produce enough gas to meet 6.5% of UK gas demand. However, the project has faced criticism from climate campaigners who argue it undermines the UK's net-zero commitments. The Jackdaw gasfield approval is seen by supporters as a pragmatic step to bolster domestic energy supplies.
Yet questions remain over the project's economic benefits. Documents revealed that the Jackdaw gasfield creates only 27 direct jobs, a modest number that critics say hardly justifies the environmental cost. The Jackdaw gasfield approval has also been described as a blow to climate campaigners, who had hoped the government would reject new fossil fuel projects.
Key Takeaways for Consumers and Investors
- UK inflation rose to 3.5% in September, driven by motor fuel costs.
- Diesel prices hit a record high above £2 a litre, with petrol above £1.70.
- Core CPI increased to 2.8%, indicating broader price pressures.
- The Bank of England is expected to raise interest rates next month.
- The Jackdaw gasfield approval aims to boost domestic energy security but creates few jobs.
Comparing Inflation Drivers: August vs September
| Category | August 2025 | September 2025 | Change |
|---|---|---|---|
| CPI (annual) | 3.1% | 3.5% | +0.4 pp |
| Core CPI (annual) | 2.6% | 2.8% | +0.2 pp |
| Motor fuel inflation | — | Highest since Aug 2022 | — |
| Diesel price (per litre) | — | >£2.00 | Record high |
| Petrol price (per litre) | — | >£1.70 | — |
What to Watch Next
All eyes will be on the Bank of England's November meeting, where policymakers will weigh the inflation data against signs of economic slowdown. Any rate rise could further squeeze households and businesses already facing higher energy bills.
Meanwhile, the government's energy strategy will remain under scrutiny. The Jackdaw North Sea gasfield approval is likely to be both praised for enhancing energy security and criticised for its limited job creation and climate impact. How these tensions resolve will shape the UK's economic and environmental landscape in the months ahead.
For a deeper look at the Jackdaw decision and its implications for UK energy security, see our analysis of the Jackdaw gasfield approval and its climate impact. The project's approval has also been framed as a blow to climate campaigners, highlighting the difficult trade-offs involved.
Critics have pointed to the small number of direct roles created as evidence that the economic benefits are overstated. Indeed, documents reveal that the Jackdaw gasfield creates only 27 jobs, raising questions about its value for money. For a broader perspective on the project, read our report on what the Jackdaw approval means for UK energy.
The timing of the decision is also notable, coming after the North Sea gasfield decision was delayed until after the Holborn byelection. This political context adds another layer to the debate. As inflation continues to bite, the surge in motor fuel prices remains a key concern for policymakers and consumers alike.
FAQ
What caused UK inflation to rise to 3.5%?
The rise was primarily driven by transport costs, especially motor fuels, which saw the fastest inflation rate since August 2022. Diesel prices topped £2 a litre, and petrol rose above £1.70, influenced by geopolitical tensions and the closure of the Strait of Hormuz.
How does the Jackdaw gasfield approval affect the UK economy?
The Jackdaw gasfield is expected to produce enough gas to meet 6.5% of UK gas demand, enhancing energy security. However, it creates only 27 direct jobs, raising questions about its economic benefits. The approval also sparks debate over climate commitments.
Will the Bank of England raise interest rates next month?
Economists widely expect the Bank of England to raise interest rates in November to combat rising inflation. The decision will depend on whether policymakers believe inflation will remain persistently high.
How does the inflation rate compare to previous months?
CPI rose from 3.1% in August to 3.5% in September, while core CPI increased from 2.6% to 2.8%. Motor fuel inflation reached its highest level since August 2022.